1 /* 2 * drivers/s390/char/monreader.c 3 * 4 * Character device driver for reading z/VM *MONITOR service records. 5 * 6 * Copyright (C) 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH. 7 * 8 * Author: Gerald Schaefer <geraldsc@de.ibm.com> 9 */ 10 11 #include <linux/module.h> 12 #include <linux/moduleparam.h> 13 #include <linux/init.h> 14 #include <linux/errno.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/miscdevice.h> 18 #include <linux/ctype.h> 19 #include <linux/spinlock.h> 20 #include <linux/interrupt.h> 21 #include <asm/uaccess.h> 22 #include <asm/ebcdic.h> 23 #include <asm/extmem.h> 24 #include <linux/poll.h> 25 #include "../net/iucv.h" 26 27 28 //#define MON_DEBUG /* Debug messages on/off */ 29 30 #define MON_NAME "monreader" 31 32 #define P_INFO(x...) printk(KERN_INFO MON_NAME " info: " x) 33 #define P_ERROR(x...) printk(KERN_ERR MON_NAME " error: " x) 34 #define P_WARNING(x...) printk(KERN_WARNING MON_NAME " warning: " x) 35 36 #ifdef MON_DEBUG 37 #define P_DEBUG(x...) printk(KERN_DEBUG MON_NAME " debug: " x) 38 #else 39 #define P_DEBUG(x...) do {} while (0) 40 #endif 41 42 #define MON_COLLECT_SAMPLE 0x80 43 #define MON_COLLECT_EVENT 0x40 44 #define MON_SERVICE "*MONITOR" 45 #define MON_IN_USE 0x01 46 #define MON_MSGLIM 255 47 48 static char mon_dcss_name[9] = "MONDCSS\0"; 49 50 struct mon_msg { 51 u32 pos; 52 u32 mca_offset; 53 iucv_MessagePending local_eib; 54 char msglim_reached; 55 char replied_msglim; 56 }; 57 58 struct mon_private { 59 u16 pathid; 60 iucv_handle_t iucv_handle; 61 struct mon_msg *msg_array[MON_MSGLIM]; 62 unsigned int write_index; 63 unsigned int read_index; 64 atomic_t msglim_count; 65 atomic_t read_ready; 66 atomic_t iucv_connected; 67 atomic_t iucv_severed; 68 }; 69 70 static unsigned long mon_in_use = 0; 71 72 static unsigned long mon_dcss_start; 73 static unsigned long mon_dcss_end; 74 75 static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue); 76 static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue); 77 78 static u8 iucv_host[8] = {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}; 79 80 static u8 user_data_connect[16] = { 81 /* Version code, must be 0x01 for shared mode */ 82 0x01, 83 /* what to collect */ 84 MON_COLLECT_SAMPLE | MON_COLLECT_EVENT, 85 /* DCSS name in EBCDIC, 8 bytes padded with blanks */ 86 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 87 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 88 }; 89 90 static u8 user_data_sever[16] = { 91 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 92 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 93 }; 94 95 96 /****************************************************************************** 97 * helper functions * 98 *****************************************************************************/ 99 /* 100 * Create the 8 bytes EBCDIC DCSS segment name from 101 * an ASCII name, incl. padding 102 */ 103 static inline void 104 dcss_mkname(char *ascii_name, char *ebcdic_name) 105 { 106 int i; 107 108 for (i = 0; i < 8; i++) { 109 if (ascii_name[i] == '\0') 110 break; 111 ebcdic_name[i] = toupper(ascii_name[i]); 112 }; 113 for (; i < 8; i++) 114 ebcdic_name[i] = ' '; 115 ASCEBC(ebcdic_name, 8); 116 } 117 118 /* 119 * print appropriate error message for segment_load()/segment_type() 120 * return code 121 */ 122 static void 123 mon_segment_warn(int rc, char* seg_name) 124 { 125 switch (rc) { 126 case -ENOENT: 127 P_WARNING("cannot load/query segment %s, does not exist\n", 128 seg_name); 129 break; 130 case -ENOSYS: 131 P_WARNING("cannot load/query segment %s, not running on VM\n", 132 seg_name); 133 break; 134 case -EIO: 135 P_WARNING("cannot load/query segment %s, hardware error\n", 136 seg_name); 137 break; 138 case -ENOTSUPP: 139 P_WARNING("cannot load/query segment %s, is a multi-part " 140 "segment\n", seg_name); 141 break; 142 case -ENOSPC: 143 P_WARNING("cannot load/query segment %s, overlaps with " 144 "storage\n", seg_name); 145 break; 146 case -EBUSY: 147 P_WARNING("cannot load/query segment %s, overlaps with " 148 "already loaded dcss\n", seg_name); 149 break; 150 case -EPERM: 151 P_WARNING("cannot load/query segment %s, already loaded in " 152 "incompatible mode\n", seg_name); 153 break; 154 case -ENOMEM: 155 P_WARNING("cannot load/query segment %s, out of memory\n", 156 seg_name); 157 break; 158 case -ERANGE: 159 P_WARNING("cannot load/query segment %s, exceeds kernel " 160 "mapping range\n", seg_name); 161 break; 162 default: 163 P_WARNING("cannot load/query segment %s, return value %i\n", 164 seg_name, rc); 165 break; 166 } 167 } 168 169 static inline unsigned long 170 mon_mca_start(struct mon_msg *monmsg) 171 { 172 return monmsg->local_eib.ln1msg1.iprmmsg1_u32; 173 } 174 175 static inline unsigned long 176 mon_mca_end(struct mon_msg *monmsg) 177 { 178 return monmsg->local_eib.ln1msg2.ipbfln1f; 179 } 180 181 static inline u8 182 mon_mca_type(struct mon_msg *monmsg, u8 index) 183 { 184 return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index); 185 } 186 187 static inline u32 188 mon_mca_size(struct mon_msg *monmsg) 189 { 190 return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1; 191 } 192 193 static inline u32 194 mon_rec_start(struct mon_msg *monmsg) 195 { 196 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4)); 197 } 198 199 static inline u32 200 mon_rec_end(struct mon_msg *monmsg) 201 { 202 return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8)); 203 } 204 205 static inline int 206 mon_check_mca(struct mon_msg *monmsg) 207 { 208 if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) || 209 (mon_rec_start(monmsg) < mon_dcss_start) || 210 (mon_rec_end(monmsg) > mon_dcss_end) || 211 (mon_mca_type(monmsg, 0) == 0) || 212 (mon_mca_size(monmsg) % 12 != 0) || 213 (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) || 214 (mon_mca_end(monmsg) > mon_dcss_end) || 215 (mon_mca_start(monmsg) < mon_dcss_start) || 216 ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0))) 217 { 218 P_DEBUG("READ, IGNORED INVALID MCA\n\n"); 219 return -EINVAL; 220 } 221 return 0; 222 } 223 224 static inline int 225 mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv) 226 { 227 u8 prmmsg[8]; 228 int rc; 229 230 P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = " 231 "0x%08X\n\n", 232 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid, 233 monmsg->local_eib.iptrgcls); 234 rc = iucv_reply_prmmsg(monmsg->local_eib.ippathid, 235 monmsg->local_eib.ipmsgid, 236 monmsg->local_eib.iptrgcls, 237 0, prmmsg); 238 atomic_dec(&monpriv->msglim_count); 239 if (likely(!monmsg->msglim_reached)) { 240 monmsg->pos = 0; 241 monmsg->mca_offset = 0; 242 monpriv->read_index = (monpriv->read_index + 1) % 243 MON_MSGLIM; 244 atomic_dec(&monpriv->read_ready); 245 } else 246 monmsg->replied_msglim = 1; 247 if (rc) { 248 P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc); 249 return -EIO; 250 } 251 return 0; 252 } 253 254 static inline struct mon_private * 255 mon_alloc_mem(void) 256 { 257 int i,j; 258 struct mon_private *monpriv; 259 260 monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL); 261 if (!monpriv) { 262 P_ERROR("no memory for monpriv\n"); 263 return NULL; 264 } 265 for (i = 0; i < MON_MSGLIM; i++) { 266 monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg), 267 GFP_KERNEL); 268 if (!monpriv->msg_array[i]) { 269 P_ERROR("open, no memory for msg_array\n"); 270 for (j = 0; j < i; j++) 271 kfree(monpriv->msg_array[j]); 272 return NULL; 273 } 274 } 275 return monpriv; 276 } 277 278 static inline void 279 mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv) 280 { 281 #ifdef MON_DEBUG 282 u8 msg_type[2], mca_type; 283 unsigned long records_len; 284 285 records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1; 286 287 memcpy(msg_type, &monmsg->local_eib.iptrgcls, 2); 288 EBCASC(msg_type, 2); 289 mca_type = mon_mca_type(monmsg, 0); 290 EBCASC(&mca_type, 1); 291 292 P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n", 293 monpriv->read_index, monpriv->write_index); 294 P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n", 295 monmsg->local_eib.ippathid, monmsg->local_eib.ipmsgid, 296 monmsg->local_eib.iptrgcls); 297 P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n", 298 msg_type[0], msg_type[1], mca_type ? mca_type : 'X', 299 mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2)); 300 P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n", 301 mon_mca_start(monmsg), mon_mca_end(monmsg)); 302 P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n", 303 mon_rec_start(monmsg), mon_rec_end(monmsg), records_len); 304 if (mon_mca_size(monmsg) > 12) 305 P_DEBUG("READ, MORE THAN ONE MCA\n\n"); 306 #endif 307 } 308 309 static inline void 310 mon_next_mca(struct mon_msg *monmsg) 311 { 312 if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12)) 313 return; 314 P_DEBUG("READ, NEXT MCA\n\n"); 315 monmsg->mca_offset += 12; 316 monmsg->pos = 0; 317 } 318 319 static inline struct mon_msg * 320 mon_next_message(struct mon_private *monpriv) 321 { 322 struct mon_msg *monmsg; 323 324 if (!atomic_read(&monpriv->read_ready)) 325 return NULL; 326 monmsg = monpriv->msg_array[monpriv->read_index]; 327 if (unlikely(monmsg->replied_msglim)) { 328 monmsg->replied_msglim = 0; 329 monmsg->msglim_reached = 0; 330 monmsg->pos = 0; 331 monmsg->mca_offset = 0; 332 P_WARNING("read, message limit reached\n"); 333 monpriv->read_index = (monpriv->read_index + 1) % 334 MON_MSGLIM; 335 atomic_dec(&monpriv->read_ready); 336 return ERR_PTR(-EOVERFLOW); 337 } 338 return monmsg; 339 } 340 341 342 /****************************************************************************** 343 * IUCV handler * 344 *****************************************************************************/ 345 static void 346 mon_iucv_ConnectionComplete(iucv_ConnectionComplete *eib, void *pgm_data) 347 { 348 struct mon_private *monpriv = (struct mon_private *) pgm_data; 349 350 P_DEBUG("IUCV connection completed\n"); 351 P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = " 352 "0x%02X, Sample = 0x%02X\n", 353 eib->ipuser[0], eib->ipuser[1], eib->ipuser[2]); 354 atomic_set(&monpriv->iucv_connected, 1); 355 wake_up(&mon_conn_wait_queue); 356 } 357 358 static void 359 mon_iucv_ConnectionSevered(iucv_ConnectionSevered *eib, void *pgm_data) 360 { 361 struct mon_private *monpriv = (struct mon_private *) pgm_data; 362 363 P_ERROR("IUCV connection severed with rc = 0x%X\n", 364 (u8) eib->ipuser[0]); 365 atomic_set(&monpriv->iucv_severed, 1); 366 wake_up(&mon_conn_wait_queue); 367 wake_up_interruptible(&mon_read_wait_queue); 368 } 369 370 static void 371 mon_iucv_MessagePending(iucv_MessagePending *eib, void *pgm_data) 372 { 373 struct mon_private *monpriv = (struct mon_private *) pgm_data; 374 375 P_DEBUG("IUCV message pending\n"); 376 memcpy(&monpriv->msg_array[monpriv->write_index]->local_eib, eib, 377 sizeof(iucv_MessagePending)); 378 if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) { 379 P_WARNING("IUCV message pending, message limit (%i) reached\n", 380 MON_MSGLIM); 381 monpriv->msg_array[monpriv->write_index]->msglim_reached = 1; 382 } 383 monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM; 384 atomic_inc(&monpriv->read_ready); 385 wake_up_interruptible(&mon_read_wait_queue); 386 } 387 388 static iucv_interrupt_ops_t mon_iucvops = { 389 .ConnectionComplete = mon_iucv_ConnectionComplete, 390 .ConnectionSevered = mon_iucv_ConnectionSevered, 391 .MessagePending = mon_iucv_MessagePending, 392 }; 393 394 /****************************************************************************** 395 * file operations * 396 *****************************************************************************/ 397 static int 398 mon_open(struct inode *inode, struct file *filp) 399 { 400 int rc, i; 401 struct mon_private *monpriv; 402 403 /* 404 * only one user allowed 405 */ 406 if (test_and_set_bit(MON_IN_USE, &mon_in_use)) 407 return -EBUSY; 408 409 monpriv = mon_alloc_mem(); 410 if (!monpriv) 411 return -ENOMEM; 412 413 /* 414 * Register with IUCV and connect to *MONITOR service 415 */ 416 monpriv->iucv_handle = iucv_register_program("my_monreader ", 417 MON_SERVICE, 418 NULL, 419 &mon_iucvops, 420 monpriv); 421 if (!monpriv->iucv_handle) { 422 P_ERROR("failed to register with iucv driver\n"); 423 rc = -EIO; 424 goto out_error; 425 } 426 P_INFO("open, registered with IUCV\n"); 427 428 rc = iucv_connect(&monpriv->pathid, MON_MSGLIM, user_data_connect, 429 MON_SERVICE, iucv_host, IPRMDATA, NULL, NULL, 430 monpriv->iucv_handle, NULL); 431 if (rc) { 432 P_ERROR("iucv connection to *MONITOR failed with " 433 "IPUSER SEVER code = %i\n", rc); 434 rc = -EIO; 435 goto out_unregister; 436 } 437 /* 438 * Wait for connection confirmation 439 */ 440 wait_event(mon_conn_wait_queue, 441 atomic_read(&monpriv->iucv_connected) || 442 atomic_read(&monpriv->iucv_severed)); 443 if (atomic_read(&monpriv->iucv_severed)) { 444 atomic_set(&monpriv->iucv_severed, 0); 445 atomic_set(&monpriv->iucv_connected, 0); 446 rc = -EIO; 447 goto out_unregister; 448 } 449 P_INFO("open, established connection to *MONITOR service\n\n"); 450 filp->private_data = monpriv; 451 return nonseekable_open(inode, filp); 452 453 out_unregister: 454 iucv_unregister_program(monpriv->iucv_handle); 455 out_error: 456 for (i = 0; i < MON_MSGLIM; i++) 457 kfree(monpriv->msg_array[i]); 458 kfree(monpriv); 459 clear_bit(MON_IN_USE, &mon_in_use); 460 return rc; 461 } 462 463 static int 464 mon_close(struct inode *inode, struct file *filp) 465 { 466 int rc, i; 467 struct mon_private *monpriv = filp->private_data; 468 469 /* 470 * Close IUCV connection and unregister 471 */ 472 rc = iucv_sever(monpriv->pathid, user_data_sever); 473 if (rc) 474 P_ERROR("close, iucv_sever failed with rc = %i\n", rc); 475 else 476 P_INFO("close, terminated connection to *MONITOR service\n"); 477 478 rc = iucv_unregister_program(monpriv->iucv_handle); 479 if (rc) 480 P_ERROR("close, iucv_unregister failed with rc = %i\n", rc); 481 else 482 P_INFO("close, unregistered with IUCV\n"); 483 484 atomic_set(&monpriv->iucv_severed, 0); 485 atomic_set(&monpriv->iucv_connected, 0); 486 atomic_set(&monpriv->read_ready, 0); 487 atomic_set(&monpriv->msglim_count, 0); 488 monpriv->write_index = 0; 489 monpriv->read_index = 0; 490 491 for (i = 0; i < MON_MSGLIM; i++) 492 kfree(monpriv->msg_array[i]); 493 kfree(monpriv); 494 clear_bit(MON_IN_USE, &mon_in_use); 495 return 0; 496 } 497 498 static ssize_t 499 mon_read(struct file *filp, char __user *data, size_t count, loff_t *ppos) 500 { 501 struct mon_private *monpriv = filp->private_data; 502 struct mon_msg *monmsg; 503 int ret; 504 u32 mce_start; 505 506 monmsg = mon_next_message(monpriv); 507 if (IS_ERR(monmsg)) 508 return PTR_ERR(monmsg); 509 510 if (!monmsg) { 511 if (filp->f_flags & O_NONBLOCK) 512 return -EAGAIN; 513 ret = wait_event_interruptible(mon_read_wait_queue, 514 atomic_read(&monpriv->read_ready) || 515 atomic_read(&monpriv->iucv_severed)); 516 if (ret) 517 return ret; 518 if (unlikely(atomic_read(&monpriv->iucv_severed))) 519 return -EIO; 520 monmsg = monpriv->msg_array[monpriv->read_index]; 521 } 522 523 if (!monmsg->pos) { 524 monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset; 525 mon_read_debug(monmsg, monpriv); 526 } 527 if (mon_check_mca(monmsg)) 528 goto reply; 529 530 /* read monitor control element (12 bytes) first */ 531 mce_start = mon_mca_start(monmsg) + monmsg->mca_offset; 532 if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) { 533 count = min(count, (size_t) mce_start + 12 - monmsg->pos); 534 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, 535 count); 536 if (ret) 537 return -EFAULT; 538 monmsg->pos += count; 539 if (monmsg->pos == mce_start + 12) 540 monmsg->pos = mon_rec_start(monmsg); 541 goto out_copy; 542 } 543 544 /* read records */ 545 if (monmsg->pos <= mon_rec_end(monmsg)) { 546 count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos 547 + 1); 548 ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, 549 count); 550 if (ret) 551 return -EFAULT; 552 monmsg->pos += count; 553 if (monmsg->pos > mon_rec_end(monmsg)) 554 mon_next_mca(monmsg); 555 goto out_copy; 556 } 557 reply: 558 ret = mon_send_reply(monmsg, monpriv); 559 return ret; 560 561 out_copy: 562 *ppos += count; 563 return count; 564 } 565 566 static unsigned int 567 mon_poll(struct file *filp, struct poll_table_struct *p) 568 { 569 struct mon_private *monpriv = filp->private_data; 570 571 poll_wait(filp, &mon_read_wait_queue, p); 572 if (unlikely(atomic_read(&monpriv->iucv_severed))) 573 return POLLERR; 574 if (atomic_read(&monpriv->read_ready)) 575 return POLLIN | POLLRDNORM; 576 return 0; 577 } 578 579 static struct file_operations mon_fops = { 580 .owner = THIS_MODULE, 581 .open = &mon_open, 582 .release = &mon_close, 583 .read = &mon_read, 584 .poll = &mon_poll, 585 }; 586 587 static struct miscdevice mon_dev = { 588 .name = "monreader", 589 .devfs_name = "monreader", 590 .fops = &mon_fops, 591 .minor = MISC_DYNAMIC_MINOR, 592 }; 593 594 /****************************************************************************** 595 * module init/exit * 596 *****************************************************************************/ 597 static int __init 598 mon_init(void) 599 { 600 int rc; 601 602 if (!MACHINE_IS_VM) { 603 P_ERROR("not running under z/VM, driver not loaded\n"); 604 return -ENODEV; 605 } 606 607 rc = segment_type(mon_dcss_name); 608 if (rc < 0) { 609 mon_segment_warn(rc, mon_dcss_name); 610 return rc; 611 } 612 if (rc != SEG_TYPE_SC) { 613 P_ERROR("segment %s has unsupported type, should be SC\n", 614 mon_dcss_name); 615 return -EINVAL; 616 } 617 618 rc = segment_load(mon_dcss_name, SEGMENT_SHARED, 619 &mon_dcss_start, &mon_dcss_end); 620 if (rc < 0) { 621 mon_segment_warn(rc, mon_dcss_name); 622 return -EINVAL; 623 } 624 dcss_mkname(mon_dcss_name, &user_data_connect[8]); 625 626 rc = misc_register(&mon_dev); 627 if (rc < 0 ) { 628 P_ERROR("misc_register failed, rc = %i\n", rc); 629 goto out; 630 } 631 P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n", 632 mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end, 633 mon_dcss_end - mon_dcss_start + 1); 634 return 0; 635 636 out: 637 segment_unload(mon_dcss_name); 638 return rc; 639 } 640 641 static void __exit 642 mon_exit(void) 643 { 644 segment_unload(mon_dcss_name); 645 WARN_ON(misc_deregister(&mon_dev) != 0); 646 return; 647 } 648 649 650 module_init(mon_init); 651 module_exit(mon_exit); 652 653 module_param_string(mondcss, mon_dcss_name, 9, 0444); 654 MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR " 655 "service, max. 8 chars. Default is MONDCSS"); 656 657 MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>"); 658 MODULE_DESCRIPTION("Character device driver for reading z/VM " 659 "monitor service records."); 660 MODULE_LICENSE("GPL"); 661